Instead of a grouping of bubbles that creates pentagons, it’s a single, spherelike bubble that is made up of pentagons (as if one bubble has been plucked from the foam, sides intact). If you fold a series of pentagons together so no holes remain, you’re left with something close to a sphere. This is the basic structure of the bubble sweater. The blouson shape of this pullover has an Eighties feel. A narrow (but not tight) sleeve keeps the overall look flattering even though the body is oversized.